It takes two to get one in trouble. – Always homing, fixed 3-second fuse time and increased damage. After sticking to an enemy, it deals damage over time until the target dies or the grenade detonates. Upon exploding, releases several life orbs equivalent to the child grenade count to heal allies.
Usage & Description
Instead of releasing child grenades upon detonation, the Kiss of Death seeks out and sticks to the target's face dealing constant elemental status damage for the length of the fuse time, including explosive damage. This makes the Kiss of Death less effective than the standard counterpart for dealing with several targets but instead deals massive damage to a single enemy.
In Borderlands 2, Hyperius the Invincible has a chance to drop the Kiss of Death, allowing for multiple copies to be acquired in a single playthrough.
Before Borderlands: The Pre-Sequel's 1.07 patch, the chest containing Kiss of Death (Moxxi's Toy Box) could be reopened after it disappears in the main story. It would respawn when the Vault Hunter entered Concordia from Triton Flats, either using Moxxi's Back Door past the slot machines in Moxxi's bar, or the main door by the Black Market, or from The Meriff's Office. This bug allowed for multiple copies of the Vibra-Pulse, Slammer, and Kiss of Death to be obtained.
The Kiss of Death refers to a kiss given to one who has committed an act of betrayal and is marked for death.
Borderlands 2 - Grenade Mods - Kiss of Death (Transfusion)